Field of the Invention
The present invention relates to power supply apparatuses and control methods, and particularly relates to a power supply apparatus including a unit which controls an on state and an off state of power supply to a load, a printer, and a control method.
Description of the Related Art
In recent years, the number of nozzles which eject ink is increased so that a printing speed and printing resolution are improved in inkjet recording apparatus (hereinafter also referred to as a “recording apparatus”). For example, in a case of a recording apparatus employing a thermal method, a heater is disposed in a position near an ink ejection port and electric power is supplied to the heater so that ink is instantaneously transformed into bubbles and the ink is ejected by kinetic energy of the bubbles.
In such a recording apparatus, an amount of electric power consumed at a time of image forming is changed depending on density of an image. In a case where an image of high density is to be formed, a large number of nozzle driving heaters are instantaneously turned on so as to eject a large amount of ink on a sheet surface, and large current is supplied to a head including the nozzles in a short time.
In a case where large current is to be instantaneously supplied, impedance of a power source is required to be reduced, and therefore, a printer configured such that an electrolytic capacitor having a small equivalent series resistance value and a large capacitance is connected to a power source line near a recording head has been widely used (refer to Japanese Patent Laid-Open No. 2009-286096).
In Japanese Patent Laid-Open No. 2009-286096, a push-pull circuit which restricts current so that inrush current is not generated when charge to the electrolytic capacitor or discharge from the electrolytic capacitor is performed is provided.
Here, in a case where an electrolytic capacitor having a large capacitance is connected to a head power source circuit, it is likely that a charge time of the electrolytic capacitor becomes long. Therefore, if large current is supplied to the power source circuit so that the charge time of the electrolytic capacitor is reduced, it is difficult to detect failure of a device including the power source circuit and a head which is caused by short-circuit or the like.